SIGNATURE INSERTER

A high speed signature inserter packer box to operate with a saddle stitcher at a rate in excess of 225 books per minute includes a very simple and rapid way to convert from operation with a feed hopper signature supply to operation with a stream feeder signature supply. The inserter packer box also has a novel arrangement for controlling the trailing end portion of a signature on the extracting drum in the area where it is grasped by the transfer drum grippers. A low volume, low velocity air stream blows through said area toward the transfer drum to deflect the trailing end portion into a recess in the transfer drum periphery that carries a set of grippers, and the recess is shaped to assure that the deflected trailing end portion is positioned to be grasped by the grippers.